[base] POSIX File::Unlock() didn't actually unlock file.

base/BUILD.gn

 # Copyright (c) 2013 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 import("//build/config/compiler/compiler.gni")
 import("//build/config/nacl/config.gni")
 import("//build/config/ui.gni")
 import("//testing/test.gni")
 
 if (is_android) {
@@ skipping 1285 matching lines @@
     "debug/crash_logging_unittest.cc",
     "debug/debugger_unittest.cc",
     "debug/leak_tracker_unittest.cc",
     "debug/proc_maps_linux_unittest.cc",
     "debug/stack_trace_unittest.cc",
     "debug/task_annotator_unittest.cc",
     "deferred_sequenced_task_runner_unittest.cc",
     "environment_unittest.cc",
     "file_version_info_unittest.cc",
     "files/dir_reader_posix_unittest.cc",
+    "files/file_locking_unittest.cc",
     "files/file_path_unittest.cc",
     "files/file_path_watcher_unittest.cc",
     "files/file_proxy_unittest.cc",
     "files/file_unittest.cc",
     "files/file_util_proxy_unittest.cc",
     "files/file_util_unittest.cc",
     "files/important_file_writer_unittest.cc",
     "files/memory_mapped_file_unittest.cc",
     "files/scoped_temp_dir_unittest.cc",
     "gmock_unittest.cc",
@@ skipping 214 matching lines @@
       ":base_java_unittest_support",
     ]
 
     # TODO(brettw) I think this should not be here, we should not be using
     # isolate files.
     isolate_file = "base_unittests.isolate"
   }
 
   if (is_ios) {
     sources -= [
+      "files/file_locking_unittest.cc",
       "files/file_path_watcher_unittest.cc",
       "memory/discardable_shared_memory_unittest.cc",
       "memory/shared_memory_unittest.cc",
       "process/memory_unittest.cc",
       "process/process_unittest.cc",
       "process/process_util_unittest.cc",
       "sync_socket_unittest.cc",
     ]
 
     # Pull in specific Mac files for iOS (which have been filtered out by file
@@ skipping 200 matching lines @@
 
   # GYP: //base.gyp:base_java_unittest_support
   android_library("base_java_unittest_support") {
     deps = [
       ":base_java",
     ]
     java_files =
         [ "test/android/java/src/org/chromium/base/ContentUriTestUtils.java" ]
   }
 }